Ledger-plate and section hardening furnace



.Aug. 6, 1935. STEWART ET AL $010,117

LEDGER PLATE AND SECTION HARDENING FURNACE Filed April 20, 1934 4 Sheets-Sheet 1 IIIIII law/W5 A g! 6, 1935. J. M. STEWART ETAL 2,010,117

LEDGER PLATE AND SECTION HARDENING FURNACE Filed April 20, 1934 4 Sheets-Sheet 2 RAN M,

Q No wwxg www RN m RH 4Sheets-Sheet 3 Filed April 20, 1934 J. M. STEWART ET AL 1 Twm 8N Wk 1 LEDGER PLATE AND SECTION HARDENING FURNACE Hm 18mm Aug. 6, 1935.

,1 I Q w J. M. STEWAR'IJ ETAL 2,010,117

LEDGER PLATE AND SECTION HARDENING FURNACE 4 Sheets-Sheet 4 Filed April 20, 1934 edges require Patented Aug. 6,

UNITED STATES PATENT OFFICE The invention relates particularly to a ledger plate and section hardening furnace.

Ledger plates and knife sections as used in the cutting mechanisms of being better that such soft and tough. It is also of great advantage that the heat treatment of form.

With the chain conveyor types of furnaces for this purpose now commonly used, a chain carries the parts through the furnace.

chains dissipate a lot of fuel and lack of uniform heat application to the be heated. Further, if the parts are not placed on the conveyor, the heat treatment of the cutting edges varies obj ectionably and, further, there is no control of the fire to prevent hardening of the body portions, which should reparts to precisely main preferably tough the working conditions for attendants of such machines are repelling, due to the terrific heat, especially in the summer time. represents wasted fuel and adds much to the cost of the hardening operation.

The object of the present invention is to provide an improved furnace which uniformly along their cutting edges only, and leave the body portions thereof tough and relatively soft.

Another object is to speed up the heat operation and materially increase the capacity of work. done by a single Still another object is to provide a machine of this kind which will no ing fuel expense and bettering working conditions for the attendants.

Another object is to p ly simple, foolproof, heat treating furnace for the purpose mentioned.

It is also an object to provide improved feeding and discharging mechanisms for such a furnace.

While throughout this disclosure the heat. treatment will be described heat treatment.

In the accompanying shown by way of illustrating the principle of the invention, a structure f Briefly, in this embed heat treatment to harden them, so that in use these cutting ed es will stand up. It is also desirable that the main body portions of such parts he not heat treated and hardened, it

LEDGER-PLATE AND SECTION HARDENING FURNACE ApplicationApril 20, 1934, sci-m1 No. 721,420

furnace comprises a pair of spaced standards having their adjacent faces formed to receive and guide ledger plates passing down therebetween by gravity. A pair of upright burner blocks are connected to the standards for burning gas, or other appropriate fuel, and direct the fire against the cutting edges of the ledgers arranged in a stack between the standards, the burner blocks being so arranged that the fire comes from opposite directions, whereby the two opposite edges of the ledgers canbe simultaneously heated. A feeding mechanism is provided to supply ledgers automatically to the heating chamber, and other means is operative to eject heated ledgers and deliver them to a quenching bath. So much will sufiice for the present to impart a general idea of the mechanism presently to be described in detail.

In the drawings:

Figure 1 is a plan View of the machine;

Figure 2 is a side elevational View of the machine;

Figure 3 is a horizontal, detail, cross sectional view through the heating chamber and burner, as viewed along the line 3-3 appearing in Figure 6;

Figure! is an end view of the machine;

Figure 5 is adetail, fragmentary, elevational View of the discharge wheel for ejecting heated ledgers from the furnace;

Figure 6 is a vertical, cross sectional view through the machine, as viewed along the section line 6-6 of Figure 2, looking in the direction of the arrows;

Figure '7 is a detail, cross sectional view through the automatic feeding mechanism, as seen along the line 'I--'I appearing in Figure 6;

Figure 8 is a detail, elevational view, partly in section, to illustrate the structure and operation of the feeding mechanism; and,

Figure 9 is a cross sectional View, as seen along the line 9-9- of Figure 4.

The heating furnace is carried on a foundatiorr structure composed of a pair of spaced base beams 1.0-, each having at its ends gusset plates i l for securing uprights I! in place. Each pair of uprights I2 carries a horizontal channel beam I3, said beams l3 being secured to the uprights by gussets I4. Thus, the main supporting structure comprises a pair of spaced floor beams 10, four uprights l2, and a pair of raised, spaced cross-beams [3 corresponding to the two floor beams H).

Secured to the ends of one of the beams I3 are a. pair of upright beams l5 and I6, across the upper ends of which is connected a cross chan- John M.

9 Claims.

harvesters having cutting portions remain relatively the cutting edges be uni- The conveyor the heat, causing waste of and relatively soft. Also,

All of this lost heat will heat such parts treating machine.

t Waste heat, thereby savrovide a compact,.relativefor ledgers of mowers and sheets of drawings there is or heating. ledger plates. iment of the invention, the

nel beam l7. As shown in Figure 6, each beam 43 carries a water manifold or box 58, on which is mounted the base portions E9 of a pair of spaced upright standards 2t, which, as shown in section in Figure 3, are hollow, as at 2!, for the circulation of water, and further are formed on their adjacent faces to receive and guide ledgers, one of which is shown at 22 in said figure. Connected to the sides of the standards 26 are hollow burner blocks 23, in each of which is arranged a burner 25 having, as shown in Figure 6, a plurality of spaced ribs 25, between which are rows of jets 26 for jetting fire into the burner chamher, or fire beX, 2'5, in which the ledgers 22 are centrally arranged so that their opposite cutting edges may be evenly exposed to the fire.

Extending from the upright beam 36 is an angle bar 28 joined at its opposite end by a gusset 29 to a supporting post 38. Spaced in parallel from the bar 23 is a pair of angle bars 28 supported at one end from the beam H by hangers 28 as best shown in Figure 9, and one of them at its opposite end being connected by a gusset 29 with a vertical post 39' and the other bar 28 being supported on the cross beam 3| and forming with both posts 3E], 36 a supporting frame structure for a horizontal platform 32. Another platform 33 is mounted on angle bars 34 supported at the upper ends of the beams i5 and i6. An outrigger support 35 is connected to the platform, as shown in Figure 2, for a purpose later to appear.

At a right angle to the support 35 are a pair of channel beams 36 arranged horizontally, back to back, and in spaced relation, said beams being supported at one end by legs 3? resting on the platform 33, While at their other end these beams are carried on blocks 38 secured to horizontal angle bars 39 supported by brackets All in turn mounted on the beam 28. The intermediate portions of the channels 36 rest on blocks 4! carried on the channel l'l.

An improved feeding mechanism for moving magazines containing a stack of ledgers to the heating chamber of the furnace is provided. As"

shown in Figure 7, each channel 36 is flanked on its inner face by a plate 52 secured by bolts 43 to the channel 36. These bolts 43 also fasten to the channels 36 a plate 44 of less height than the first mentioned plates 62, there being a spacer plate 45 also held by the bolts 43 between each plate 42 and 44. Slidably resting on the top edges of the plates d2 are the base plates Q6 of upright magazines 47., which contain a load of stacked ledgers 22. The plates 65 of these magazines are held to the rails 42 by plates 48 fastened to the tops of the channels 36, as shown best in Figure 7.

As shown further in Figure 7, and in Figure 6, a pair of spaced plates d9 are connected at their upper edges by a plate 59, said plates 49, 58 forming a horizontal channel member between the plates ti l, with the top plate 50 slidably guided and resting on the top edges of the guide rail plates 44. The top plate 5a of this channeled slide structure is formed in the present embodiment with a series of four spaced openings 5i. Below each opening 5!, the structure 49, 5!] carries hinge pins 52, on each of which is pivoted, intermediate their ends, a vertically disposed feeder dog 53, each dog comprising a lower weighted end 54 and an upper hooked end 55, which hooked ends all face in the same direction and project upwardly through the holes 55.

These hook ends 54 each engage an adjacently mounted magazine base 46, as shown in Figures 6 and 8. At one end of the plates 39 is a hinge pin 56, to which is pivotally connected the U- shaped end 51 of a spring pressed pitman link 58 having its other end pivotally connected to the end of a crank 59 turned by a shaft 86 extending from a housing 5! containing suitable reduction gearing (not shown) and operated by the shaft 62 of an electric motor 63 carried on the platform 32.

A circuit 64 is connected to the motor 53, said circuit leading from a switch box 65 mounted between the pcsts 39 and 36'. From said switch box 55 runs a lead (55 to a photo-electric cell 6? mounted at the end of a tube 58 mounted on a leg 59 on the platform 33. The tube '58 is connected with a light receiving chamber 18 secured to one of the channels 35. At this point, the channels 36 have registering openings l through which a ray of light passes from a lamp :2 carried on the outrigger 35, there being a condenser lens 13 intermediate the light source and the slits ll, all of these parts being in line with the tube 68. The stack of ledgers in the magazine above the chamber 21; that is, when the magazinc is in feeding position, is also in line with the ray of light.

A stack of ledgers is dropped into the chamber 21 to be subjected to the fire, the bottom end of the stack L-shaped bracket 14 secured to one of the standards 20, as shown in Figure 5. A ledger discharge means is located below the chamber 2?, said means comprising a wheel 75 turnable with a horizontal axle l6 journaled in suitable bearings on a support 11 mounted on the floor adjacent the base beams lil. On the periphery of the wheel, in predetermined equidistant spacing, are a series of radial lug plates 18, arranged in spaced pairs to engage the heel of each ledger at spaced points for positively ejecting the same from the bottom of the ledger stack. These plates 78 are at such a radial distance from the center of the wheel 75 that they eject the ledgers one at a time.

This wheel 15 rotates clockwise, as seen in Figure 5, and, in front of each set of paddle plates 18, the wheel periphery has secured to it an inclined guide plate 19, whose function is to receive the ejected ledgers and direct them by gravity to a chute 80 (see Figures 2, 4 and 6), said chute in turn directing the heated ledgers to a quenching tank 8! containing oil.

This tank 8| rests on the floor adjacent the machine and contains a canvas apron conveyer 82. This conveyer is endless and inclined, as indicated in Figure 2, with its lower end near the bottom of the tank. The lower end of the endless conveyer is trained around a roller 83 journaled in the bottom of the tank, said roller having a shaft projecting to the outside of the tank where it carries a sprocket 84 driven by an outside chain 85 from a sprocket on an upper shaft 86 carrying an upper drive roller 8'! (see Figure 4) for driving the canvas conveyer 8! As shown in Figure 1, the shaft 86 carries a pulley 88 driven by a belt 89 from a pulley 90 operated by gearing in a case 9! on a base 92, said gearing being driven by an electric motor 93, also mounted on the base 92.

As appears in Figures 1, 2 and 4, the shaft 76 carrying and driving the discharge wheel 75 car ries at one end a pulley wheel 94 driven from a belt 95 trained around a pulley wheel 95 operated by a gear reducer in a housing 97, said reducer receiving power from another electric motor 98.

resting on the horizontal portion of an The burners 24 receive gaseous fuel through any suitable source of supply, such as the pipe 99, which has two branches H38 leading respectively to the two burners 24, as shown in Figures 4 and 6.

The standards 20 are water cooled to carry off heat, and the manifolds l8 similarly have water circulated through them to cool the lower end of the burner structure. Accordingly, a pipe ldl is arranged alongside one of the manifolds I8, said pipe having a branch 32 for leading water into the lower end of one of the standards 20, said water entering the bore 2! and passing upwardly to cool the standard. A water outlet pipe I03 extends from the upper end of said standard and discharges the water into a sewer N14. The pipe Iill also has a branch 895 for leading water into one of the manifolds i3. Water leaves this manifold through an outlet pipe H36 and into the sewer Hi4. Said feed pipe lili is bent up at iii! to lead water into the lower end of the other standard 2%} and into its bore 24, the water leaving the upper end thereof through an outlet pipe 108, also discharging into said sewer ms.

The opposite manifold 15 receives water from a feed pipe Ill9-simi1ar to the pipe HM, said pipe I09 having a branch H9 for directing water into the said manifold. This manifold also has a water outlet pipe (not shown)' for leading the water to the sewer.

The paddle plates 18 and the rim of the discharge wheel 15 operate in water contained in a tank HI to keep said wheel cool, said tank standing on the floor beneath the wheel.

In the operation of the improved hardening furnace the chamber 2 is loaded to full capacity from top to bottom with ledger plates which fit between the adjacent inner faces of the standards 20 in such a manner that their opposite cutting edges will be exposed to the fire from the burners 24. The bottom of the ledger stack is supported on the horizontal portion of the L bracket 14. Next, a loaded magazine 41 is placed directly over the loaded chamber 21 in vertical alignment therewith; thus, providing a column or stack of ledgers closing off the light slits H, so that light from the burning lamp 12 is cut off from the photo-electric cell 61. Then the feeder rack structure 49, 5B is moved back to the position shown in Figure 6. A loaded magazine 41 is then placed on the rails 42 in front of each dog 53 in such a manner that the hooks 55 abut the base plates 46 of the magazines.

Next, the burners 24 are turned on and kept in operation for a sufficient time to maintain an even heat and properly heat those ledgers in the lower end of the heating chamber 21. Then, the motor 98 is turned on to operate the discharge Wheel 15, the paddles E8 of which eject the ledgers, one at a time, from the bottom of the stack and the bracket 14. These heated ledgers fall into the chute 8t and thence onto the conveyer 82 in the quench bath 81, said conveyer serving to take the heat treated and hardened ledgers out of the bath to any suitable point of discharge. At the same time, the wheel I5 is kept cool by passing through the water in the tank Ill; and the standard 20 and lower portion of the burner mount likewise being kept cool by the water circulating system already described.

As the heated ledgers leave the lower end of the stack, the ledgers gravitate downwardly between the standards 2o until eventually the up per end of the stack is below the level of the light slit Ii, whereupon a ray of light from the lamp 12 is detected by the electric eye 61, which-closes an electric circuit 64 in any well known manner, to energize and operate the motor 63. Thereupon, the crank 59 and pitman 58 are operated to slide the rack channel 49, 50 toward the chamber 21. The hooks 55, engaging the magazines ll, advance all of them in their properly spaced relation, so that the empty magazine ll is enaged at its base plate 46 by the adjacent advancing magazines base plate 46. In this fashion the empty magazine is slid out of the way and is displaced by the second from the left magazine (as seen in Figure 6). As this new loaded magazine comes to rest over the chamber 21, its contents gravitate thereinto to out off the light ray and cause the motor circuit 64 to be opened, which stops the motor 63, it being understood that the motor operates, in accordance with the timing of the mechanism, long enough to result in one complete revolution of the crank 59. Therefore, the structure 49, 59 moves ahead to shift the magazines, and then moves back, making one full stroke. On its back stroke, the dogs 53 are gu ded by the rounded back edges of the hooks under the plate 50 by the edge of the holes 5|, as seen in dotted lines in Figure 8, Then, when the back stroke is complete, the dogs 53 again are in position under the openings 5| where the weighted ends 54 are effective to pivot the dogs to cause their hooks 55 to move up through the holes 5! and into position again to engage and push the plates 46 of the magazines in the succeeding cycle of feed operation.

Looking to Figure 6, it will now be seen that. in the manner described, empty magazines are pushed over to the left of the chamber 21 and succeeding new, or filled, magazines are successively advanced into chamber feeding position frornthe right. The empty magazines are slid out from the left end of the guide structure 42, '48 and refilled, whereupon they are replaced on the right hand end of said guide structure. In this fashion continuous operation results.

The motor 98 for the discharge wheel is separately turned on; and the same is true for the motor 93, that drives the conveyer &2.

From this disclosure it will be seen that an improved hardening furnace for the purposes described has been provided, which achieves all of the desirable objects heretofore recited.

It is the intention to cover all changes and modifications not departing from the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

1. In a furnace of the class described, a pair of spaced vertical standards formed on their adjacent inner faces to receive and guide a stack of parts to be heat treated, said stack of parts having an exposed edge, the standards being hollow for the circulation of cooling liquid, a burner carried adjacent the standards to direct heat to the exposed edge of the work, and means comprising a manifold associated with the standards to circulate the cooling liquid therethrough.

2. In a furnace of the class described, a pair of spaced standards formed on their adjacent inner faces to receive and guide a stack of parts to be heat treated, said stack of parts having an exposed edge, means for automatically feeding parts to the topof said stack, means to eject parts from the bottom of the stack into a quenching bath, and a burner carried adjacent the standards to direct heat to the exposed edge of the work.

3. In a furnace of the class described, a vertical chamber formed by an upright structure, said chamber containing a stack of parts having an exposed edge to be heated, a burner adjacent said structure for heating said edges, an automatic feeding mechanism for supplying parts to be heated to the chamber, said mechanism being controlled by the height of the stack of parts in the chamber, and means to discharge heated parts from the lower end of the stack into a quenching bath.

4. In a furnace of the class described, a vertical chamber formed by an upright structure, said chamber containing a stack of parts having an exposed edge to be heated, a burner adjacent said structure for heating said edges, an automatic feeding mechanism for supplying parts to be heated to the chamber, said mechanism being controlled by means comprising a light source and a photo-electric cell operative when the stack of parts lowers a predetermined distance, and means to discharge heated parts from the lower end of the stack into a quenching bath.

5. In a furnace of the class described, a frame, a pair of spaced hollow standards on the frame forming a heating chamber, said standards having their adjacent faces formed to receive a stack of parts having opposite edges to be heat treated, a pair of opposed burners adjacent the standards to direct heat to said edges, and means including a manifold for circulating a cooling m dium through the standards.

6. In a furnace of the class described, a frame, an upright structure forming a heating chamber open at one side to expose the edges of a stack of parts to be heated contained in the chamber, a burner closing a portion of the open side to heat the parts, means to support the parts in the chamber, means to eject the heated parts from the bottom of the stack, said means including deflectors, and a quenching bath to receive the ejected heated parts from the deflectors.

7. In a furnace of the class described, a frame, an upright structure forming a heating chamber open at one side to expose the edges of a stack of parts to be heated contained in the chamber, a burner closing a portion of the open side to heat the parts means to support the parts in the chamber, means to eject the heated parts from the bottom of the stack, said means comprising a rotatable wheel having means to engage and eject the parts from the stack, a quenching bath, and deflectors on the wheel to direct ejected parts into the bath.

8. In a furnace of the class described, a frame, an upright structure forming a heating chamber open at one side to expose the edges of a stack of parts to be heated contained in the chamber, a burner closing a portion of the open side to heat the parts, means to support the parts in the chamber, means to eject the heated parts from the bottom of the stack, means to feed upright magazines containing parts to be heated into position in vertical alignment with the chamber, and means for automatically replacing an empty magazine in line with the chamber with a loaded magazine.

9. In a furnace of the class described, a "frame, a pair of horizontal spaced Water manifolds, a pair of hollow standards carried on the manifolds, said standards being spaced apart to form an open sided chamber for carrying parts to be heat-ed, a burner adjacent the standards for directing fire through the open side to the parts, i

and means for circulating water through the manifolds and standards.

JOHN M. STEWART. WILLIAM HAL/1M. EDWARD W. COONEY. 

